E883] Proceedings of Scientific Societies. 1001 
islands until, at the end of the Cretaceous, the Andean range cut 
off the sea to the west. Since then a great Tertiary formation 
was laid down and the Amazon basin defined. The deposit made 
by the river and its branches is not older than the post-pliocene. 
Cretaceous strata occur near Pernambuco, and in these have been 
found the remains of several genera of sharks, and of a crocodile 
of the genus Hyposaurus, which occurs also in New Jersey; also 
a genus of rays (Mesedaphus). These remains indicate a horizon 
corresponding to the Maestricht chalk. A new pycnodont, Pvc- 
nodus fiabellatus, had been found at Mapiri. In the lacustrine 
ds near Bakia many fish and saurians have been found, and 
crocodiles and dinosaurs, the former indicating a horizon above 
the Pernambuco beds also occur. He thought the age would 
prove to be near the Laramie. Some pampean beds near Bahia 
as yet have yielded only one fossil, Torodon expansidens, sp. nov. 
A batrachian (Arzarthrosus Cope, gen. nov.) has been found in 
San Paolo, and is probably Permian, but may be Carboniferous. 
The pliocene vertebrates of Brazil are very distinct from those o 
orth America, but the fossils now being studied indicate marked 
similarity in earlier periods. 
April 18.—Professor Heilprin spoke of some invertebrate fos- 
sils from Santa Cruz, Patagonia. Tertiary deposits are traceable 
along nearly all the rivers of this region, and superimposed on 
those are the pampean shingle beds. The fossils greatly resem- 
ble those of N. Europe and Asia. Some forms are like those of 
our west coast. Dr. H. C. McCook spoke of the mode followed 
by orb-weaving spiders in making their snares. The foundation 
lines form an irregular polygon. After securing these the spider 
places the radiating lines alternately and almost opposite to each 
other, retiring to the center after making each attachment, This 
alternate opposition of the lines serves to strengthen the web. 
He believed the radii to be single lines. The converging point 
of the radii frequently seemed above the geometric center, prob- 
ably to resist the spider’s weight. 
April 26.—Professor E. D. Cope described the head of Diclonius 
mirabilis Leidy,a saurian allied to the Hadrosaurus of the New Jer- 
sey marl. A nearly perfect skeleton from the Laramie beds of Da- 
kota was in the speaker's possession. The head was bird-like in 
appearance, with spoon-like premaxillaries. Mr. Wortman ex- 
Pressed his belief that Ga/era macrodon from the Post-pliocene of 
Maryland should be placed in the genus Putorius, and dwelt on 
the relationships of the Mustelide; he did not attach much im- 
portance to color, size, and other individual variations. Dr. Horn 
exhibited a piece of bed-ticking from a bed the feathers in which 
had been destroyed by Attagenus megatoma. The interior sur- 
face of this ticking was converted into a fine plush by the pene- 
tration into the interstices of the material of the fine barbules of 
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